Outlet means in a thermoplastic yarn rebound texturizing apparatus

ABSTRACT

In a bounce crimping apparatus for texturizing multi-filament thermoplastic yarn including a yarn texturizing chamber, a means for introducing heated fluid into the yarn texturizing chamber for drawing yarn into the chamber, a foraminous surface transversely positioned across a longitudinal fluid outlet of the yarn texturizing chamber and a means for collecting texturized yarn in a condition substantially free from longitudinal tension; the improvement comprising means connected to a lateral outlet of the yarn texturizing chamber for conveying texturized yarn from the chamber and for compacting the yarn as the yarn moves to the means for collecting the texturized yarn.

United States Patent 91 Guenther 1 1 OUTLET MEANS [N A THERMOPLASTICYARN REBOUND TEXTURIZING APPARATUS [75] Inventor: Lloyd M. Guenther,Severna Park,

Chevron Research Company, San Francisco, Calif.

[22] Filed: Dec. 28, 1973 [21] App]. No.: 429,058

[73] Assignee:

[ June 10, 1975 3.665.567 5/1972 Clarkson M 28/14 1778.872 12/1973Newton 28/111 $780,405 12/1973 lzawa ct al 28/111 Primary Examiner-LouisK Rimrodt Attorney, Agent, or Firm-G. F. Magdehurger; .l. Stoner, .lr.;.l. A. Buchanan, Jr.

[57] ABSTRACT In a bounce crimping apparatus for texturizingmultifilament thermoplastic yarn including a yarn texturizing chamber, ameans for introducing heated fluid into the yarn texturizing chamber fordrawing yarn into the chamber, a foraminous surface transverselypositioned across a longitudinal fluid outlet of the yarn texturizingchamber and a means for collecting texturized yarn in a conditionsubstantially free from longitudinal tension; the improvement comprisingmeans connected to a lateral outlet of the yarn texturizing chamber forconveying texturized yarn from the chamber and for compacting the yarnas the yarn moves to the means for collecting the texturized yarn.

3 Claims, 4 Drawing Figures OUTLET MEANS IN A THERMOPLASTIC YARN REBOUNDTEXTURIZING APPARATUS BACKGROUND OF THE INVENTION This invention relatesto an apparatus for texturizing synthetic thermoplastic yarn. Morespecifically, the in vention relates to an improved apparatus for bouncecrimping thermoplastic yarn.

Synthetic thermoplastic yarn materials, as produced, are composed ofcontinuous, straight, smooth filaments. Such yarns have little bulk, andtheir utility in textile applications is rather limited.

In order to enhance the bulk and texture of synthetic yarns, a varietyof crimping processes have been used in the past. For thermoplasticyarns, a basic technique is to bend the yarn filaments and heat the yarnwhile the filaments are in bent or crimped configurations.

Recently, a basic advance has been achieved in texturizing thermoplasticyarn. This texturizing technique, known as a rebound or bounce crimpingprocess, yields strikingly improved results as far as crimp quality isconcerned.

Bounce crimping entails hurling yarn, by a heated fluid, through a jetin a continuous stream-like flow against a foraminous surface upon whichthe yarn impinges and from which the yarn instantaneously rebounds orbounces. The impact of the yarn upon the foraminous surface axiallybuckles and crimps individual filaments of the yarn while the heatedfluid passes through the foraminous surface. The texturized yarnprogresses without tension and substantially by rebound inertia awayfrom the crimping zone and is guided to a collection station where theyarn is heated and then cooled to heat set the crimp prior to windingupon a storage spool.

Thermoplastic yarn texturized by the foregoing bounce crimping processpossesses, inter alia, exceptional covering capability and a high degreeof resiliency as disclosed in Miller et al. US. Pat. No. 3,686,848issued Aug. 29, l972.

The basic process and apparatus for practicing the process is featuredin Clarkson US. Pat. No. 3,665,567 issued May 30, 1972. In briefsummary, the Clarkson structure entails feeding a yarn through anelongate slender tube by a jet of steam and hurling the yarnlongitudinally against a foraminous screen. The yarn is thereby crimpedor texturized and freely rebounds laterally through a passage from whichit drops down to a receiver for heat setting. The steam primarily passesthrough the foraminous screen and is collected although at least some ofthe steam whistles or hisses laterally through the tubular passage alongwith the texturized yarn. In the event yarn becomes entangled upon thescreen or within the outlet passage, a slit is provided in the lowermostportion of the laterally extending passage to permit a pair ofunderlying nip rollers to engage and extricate the yarn.

Notwithstanding singular advantages provided the synthetic textileindustry by the above-noted Clarkson bounce crimping process andapparatus, room for significant improvement remains. One area ofparticular concern from the standpoint of actual commercial yarnmanufacturing operations has been a degree of irregularity, or lack ofuniformity, in the yarns produced through use of the bounce crimpprocess. Although the mechanically severe conditions in thecrimp-producing zone are desirable as far as imparting good crimpcharucteristics to the individual filaments of the yarn is concerned,these severe conditions tend to create wide variations in the assemblyof filaments, that is, variations in the yarn body made up of themultitude of individually crimped filaments.

This point can perhaps be appreciated most easily by visualizing thesituation near the foraminous member of a bounce crimp chamber duringthe processing of a typical upholstery yarn made up of say one hundredor more individual filaments. The jet hurls the filaments endwiseagainst the foraminous member where they buckle in a somewhat randommanner and bounce away in a random array. This array is a loose, fluffy,body which tends to conform generally in contour to the shape of theoutlet opening from the crimp chamber and which varies in density alongits length. In the apparatus known prior to this invention, a guide tubeof rather large area, as compared with the area of the crimp chamberoutlet, received the fluffy yarn and established its general directionof movement away from the crimp zone. However, this large diameter guidetube permitted the yarn to buckle back and forth upon itself to asubstantial extent and afforded opportunities for protruding filamentsat one portion along the yarn length to become entangled with filamentsat another portion along the length of the yarn, thereby introducingstill further irregularities.

A swingable flapper at the outlet of the guide tube of the heretoforeknown apparatus provided some control over the yarn issuing therefrom,but the control effect was limited primarily to preventing the yarn fromrebounding too far laterally and missing the collector tube into whichit was supposed to fall. In ordinary operation, the flapper swung backand forth unpredictably in response to pressure gusts. That is,rebounding yarn impacting against the flapper would set it in mo tion ina passageopening direction, such motion would reduce the capability ofthe flapper to restrain movement of the yarn, and an erratic oscillationsystem would be established. Although this arrangement had some tendencyto consolidate the fluffy yam from the crimping zone, the consolidationeffect was far from uniform along the length of the yarn.

Wide density variations along the length of a filament yarn in atensionless state might safely be ignored in many instances because ofthe fact that these variations tend to be eliminated automatically whenthe yarn is tensioned. However, in the bounce crimp process, the yarnfrom the crimping zone is kept in the essentially tensionless stateuntil after it has been subjected to heating and cooling cycles whichserve to permanently set the thermoplastic filaments in their distortedshapes. That is, the wide variations tend to become permanentcharacteristics of the yarns and may show up as unintended anduncontrolled visual irregularities in products fabricated from the yarn.

Accordingly it would be highly desirable to provide a bounce crimpingapparatus wherein the yarn would be subjected to controlled axialcompaction immediately downstream from the crimping chamber to reduceits fluffiness and enhance the uniformity of the yarn densitycharacteristics along the length of the yarn. Further, it would behighly desirable to reduce the tendency for knotting or tangles to occurwithin an outlet passage of the texturizing apparatus.

Still further, it would be desirable to eliminate the previously notednip roller structure while maintaining a means for removing filamentswhich may occasionally be embedded or entangled within the texturizingscreen. Yet additionally. it would be desirable to reduce noisepollution generated by the bounce crimping process.

OBJECTS AND BRIEF SUMMARY OF THE INVENTION Objects In light of theforegoing, it is a general object of the invention to provide animproved yarn rebound texturizing apparatus which will obviate orminimize deficiencies and provide enhanced properties of the typepreviously described.

It is a particular object of the invention to provide an improved bouncecrimping apparatus wherein uniformity of the texturized yarn may bemaximized.

It is another object of the invention to provide an improved outletmeans for a bounce crimping apparatus wherein axial compaction of theyarn may be effected downstream from a bounce crimping chamber.

It is yet another object of the invention to provide an improved outletfor a bounce crimping apparatus wherein a smooth transition from abounce crimping chamber to an outlet conduit is achieved in a mannerwhich will facilitate axial compaction of the yarn and minimize lateralbuckling of the yarn within the outlet conduit.

It is a further object of the invention to provide an improved outletmeans for a yarn crimping chamber wherein tangles upon a foraminousbounce crimping surface may be effectively removed without the provisionof previously utilized nipping rollers.

It is still a further object of the invention to provide an improvedoutlet means for a bounce crimping apparatus which will obviate orminimize noise pollution previously associated with bounce crimpingoperations.

Brief Summary A bounce crimping apparatus according to a preferredembodiment of the invention intended to achieve at least some of theforegoing objects includes a yarn crimping chamber provided with aforaminous surface or screen against which the thermoplastic filamentsare impacted and an outlet through which the yarn bounces away from thescreen, a yarn outlet tube connected to the crimping chamber outlet, anda means for receiving the yarn from the outlet tube and heat setting itin a condition substantially free from tension. The yarn outlet tube ofthe subject invention is preferably circular in cross section andsmoothly mates with the outlet of the crimping chamber at one end forreceiving texturized yarn. The internal cross sectional area of the tubeis no greater than about twice that of the crimping chamber outlet so asto minimize buckling of the yarn back and forth upon itself as it movesthrough the tube. The tube is further fashioned with a bend to providegenerally uniform axial resistance to the passage of yarn therethrough,thus effecting axial compaction of the yarn. This axial compaction isfacilitated in one embodiment by the provision of a leaf springextending within the outlet tube passage near its outlet end. The tubeshould have a substantial length (at least 3 and preferably times itsdiameter) to firm up the compacted yarn in the form of a loose plug, andit should not be open to atmosphere near its inlet end lest escapingsteam in this area result in excessive noise and entanglement of loosefilaments with edge portions of the opening.

THE DRAWINGS Further objects and advantages of the invention will becomeapparent from the following detailed description taken in conjunctionwith the accompanying drawings, wherein:

FIG. 1 is a front elevational view, partially broken away, of a bouncecrimping apparatus for texturizing synthetic thermoplastic continuousfilament yarns;

FIG. 2 is a cross sectional view taken along section line 2-2 in FIG. 1and discloses a bounce crimping chamber and an improved lateral outlettube according to a preferred embodiment of the invention;

FIG. 3 is a cross sectional view taken along section line 33 in FIG. 2and discloses the cylindrical character of the improved outlet tube andthe smooth transition from the bounce crimping chamber to the outlettube; and

FIG. 4 is a bottom view of the improved outlet tube and specificallydiscloses a retaining mechanism for maintaining axial compression of theyarn within the outlet tube.

DETAILED DESCRIPTION Basic Structure of the Invention The improvement ofthe subject invention is in spe cific combination with a bounce crimpingapparatus according to the above referenced Clarkson US. Pat. No.3,665,567. The entire disclosure of this Clarkson patent is herebyincorporated by reference as though set forth at length. Briefly,however, the basic bounce crimping structure of the subject combinationinvention may be appreciated by reference to FIG. 1 which discloses anelevational view, partially broken away, of a bounce crimping apparatus10.

A multifilament synthetic thermoplastic yarn 12 is fed from a supplypackage (not shown) to a first driven godet roll 16 with skewedseparator roll 14 and then to a second driven godet roll 20 with skewedseparator roll 18. Godet rolls 16 and 20 may be heated and rolls l8 and20 advance the yarn at a much greater speed than do rolls 14 and 16 sothat the yarn 12 is drawn between the two sets of rolls.

From roll 18 the yarn l2 advances to a yarn texturizing stationindicated generally by reference character 22 and then into a heatingchamber 24 where the yarn is heated in a loose mass substantially freefrom tension. The yarn passes downstream of the heating chamber 24 intoa cooling chamber 26 where the yarn is cooled again in a loose masssubstantially free from tension. The yarn 12 is then drawn from thecooling cham ber 26 in the form ofa strand over idler rolls 27, 28 and29 by a pair of rolls 32 and 34. From godet roll 32 the yarn 12 advancesover idler roll 36 to a standard takeup mechanism where the yarn iswound in a package 38 for storage and shipment.

Referring to FIG. 2 the yarn texturizing station 22 includes a yarn tube40 which passes through a steam plenum chamber 42 formed by a plumbingtee 44, (FIG. I). The plumbing tee 44 is connected through a steam valve46 to a steam pipe 48 so that steam may be fed to the plenum chamber 42as regulated by valve 46.

The tube 40 passes completely through steam plenum chamber 42 andterminates at the upper end of a yarn passage chamber 50. The steamplenum chamber 42 fiuidically communicates with yarn passage chamber 50so that steam from the plenum chamber may pass downwardly about tube 40and into the annular space between tube 40 and an upward continuation ofthe walls defining the yarn passage chamber 50. The tube 40 is held in acoaxial posture with respect to the yarn passage chamber 50 by means ofstruts 52 on the lower end of the yarn tube 40.

Steam passes through the annular chamber and around the struts 52 to theyarn exit end of the tube 40 where the steam picks up the yarn l2exiting from the tube 40 and hurls the yarn longitudinally through yarnpassage chamber 50. As will be noted, yarn passage chamber 50 extendsbeneath the lower end of the tube 40 and is continued as a bore 54 in anadapter housing 56. The diameter of the bore 54 is the same as theinternal diameter of the yarn passage chamber 50 so that a singlediameter cylindrical passage is provided for the yarn as the yarn exitsfrom tube 40 until it reaches the level of a yarn opening 60 within theside of the adapter housing 56.

The external lower end of the adapter housing 56 has a convexconfiguration surrounding the lower end of the bore 54. A member 62having a foraminous surface, such as a screen, closes the lower endopening of the bore 54 to the passage of yarn while simultaneouslypermitting steam to longitudinally pass through the openings in thescreen 62.

The adapter housing 56 is fitted with a coaxial collar 64 which servesas an adapter for connection of the bore 54 with a steam exhaust conduit66. By the provision of the exhaust conduit, steam passing throughscreen 62 may be drawn off by a blower (not shown).

The above described components cooperate to texturize thermoplastic yarnintroduced into tube 40 by the technique ofrebound" or bounce crimping.In this connection, thermoplastic yarn 12 is heated as it advancesthrough the yarn tube 40 and is picked up by the steam at the exit endthereof. The plastic yarn is then hurled longitudinally with great forceby the downward flow of steam toward the screen 62 at the centermostpoint of the concave portion of the screen. The bulk of the steam passesthrough screen 62, while the filaments of yarn 12 are interceptedthereby to be bent and crimped by the impact and then rebound or bouncefrom screen 62 instantaneously and in a continuously moving strand-likestream to flow upwardly and to the left into an improved conveying andcompacting means 68. From the improved conveying and compacting means 68the yarn is deposited into the heating chamber 24.

As noted in FIG. 1, the heating chamber 24 consists of an outer sleeveof insulation 70 which surrounds a steam chamber 72, which in turnencompasses an inner cylindrical yarn treating chamber 74. Steam iscirculated through chamber 72 to heat the wall about the yarn treatingchamber 74, and consequently to heat the yarn contained within thechamber 74.

The rebounded texturized yarn [2 falls into the yarn receiving chamber74 in a condition substantially free of longitudinal tension. As theyarn 12 is withdrawn from the cooling chamber 26 by godet rolls 32 and34, the loose mass of yarn within the heating chamber 24 progressesdownwardly through the heating chamber.

To further assist in heating the yarn within chamber 74, hot air bleedtubes 76 are disposed vertically within the chamber 74 and are providedwith apertures spaced at regular intervals throughout the longitudinalextent thereof. Air heated in the steam chamber 72 is blown from theapertures within bleed tubes 76 into chamber 74 to circulate through themass of yarn within the chamber 74 and insure uniform heating of thetexturized yarn.

As previously noted, immediately beneath the heating chamber 24 there isdisposed a cooling chamber 26 comprising the bottom leg of a J-tubeformed by the heating chamber 24 and the cooling chamber 26. The yarnpasses through the cooling chamber 26 still in a loose untensioned mass.To assist in cooling the yarn, two air bleed tubes 78 are disposedinside and on opposite sides of the cooling chamber 26. Air at roomtemperature is blown through the cooling tubes 78 and out throughapertures within the tubes along the longitudinal length thereof tocirculate through the yarn mass to cool the yarn and exit through anopening 80 within a top portion of the cooling chamber 26.

Not until this point when the yarn has been fully heat set and cooled isthe texturized yarn subject to longitudinal tension. As noted in FIG. 1,the yarn 12 is now withdrawn from the cooling chamber 26 over a baffle82 and through an eyelet 84 which tends to remove gross tangles in theyarn. To further remove any persistant tangles a series of tension vanes86, 88, and 92 are provided. These vanes are simply thin pieces of sheetmetal shaped to close the chamber and pivot at hinges 94, 96, 98 and100, respectively, so that gravity will pivot the tension vanes againsta wall 102 of the chamber.

The yarn thus untangled advances in a substantially linear form overidler rolls 27, 28 and 29 by pull-out godet rolls 32 and 34 to be woundupon a package 38 in a conventional manner as previously noted.

IMPROVED OUTLET AND COMPACTION ASPECT OF THE INVENTION As specificallyillustrated in FIGS. 24 an improved outlet and compaction means 68 incombination with a bounce crimping apparatus, according to a preferredembodiment of the invention, comprises a cylindrical tube 104 having acircular cross section and is designed to normally extend at a first end105 into and mate with the adapter body 56. In this connection a centrallongitudinal axis of the tube 104 at the first end 105 will intersectand lie at right angles to the central longitudinal axis of the bore 54of adapter 56. The other end 106 of the outlet tube is bent downwardlyapproximately 90 with respect to the first end such that the centrallongitudinal axis of the tube at the second end extends at a right anglewith respect to the central longitudinal axis of the tube at the firstend thereof.

As specifically illustrated in FIG. 3 the internal diameter of thecircular tube 104 is slightly greater than an arcuate upper surface 107of a lateral outlet arch 108 fashioned within the adapter 56.Accordingly, texturized yarn filaments rebounding from the foraminoussurface 62 smoothly enter the outlet tube 104 without becoming tangledby sharp edges or comers between the outlet tube 104 and the adapterhousing 56. This smooth transition zone minimizes the occurrence of ablocking or jamming tendency of the texturized yarn at the outlet of theadapter 56.

Moreover, it will be noted from FIG. 3 that the internal cross sectionalarea of the tube 104 is not vastly greater than that of the adapter yarnoutlet opening defined by the screen 62 at the bottom and the arch 108at the top. This feature is important in that it has been founddesirable to inhibit buckling of the yarn back and forth upon itself asthe yarn moves along the tube 104. The loose. fluffy, yarn from thecrimping zone tends to assume the general size and shape of the adapteroutlet opening. and if this is very much smaller than the pas sage intowhich the yarn is moving there is a tendency for buckling along thelength of the yarn to cause yarn to eject intermittently and to produceirregularities in the product. It has been found, in accordance with theinvention, that such difficulties may be avoided if the internal crosssectional area of the tube 104 is in the range of from about 1 /2 toabout 2 times the area of the adapter outlet opening. Under theseconditions, there is little tendency for lateral buckling of the yarn;instead it may compress axially to substantially fill the crosssectional area of the tube 104 so that reshaping of the filamentassembly takes place smoothly and regularly.

The arcuate, approximately 90, bend in the outlet tube 104 providesresistance to the passage of texturized yarn through the tube. in thisconnection, as the yarn encounters increased resistance provided by thecurve in outlet tube 104, the yarn increases in axial compaction asschematically represented at points 110, 112 and 114. The length of thetube 104 should be in excess of 3 and at least 5 times its diameter, sothat the compaction may take place over a zone of substantial length.The outlet tube 104 progressively imparts axial compaction to thetexturized yarn to provide a loose plug of individually crimped fibers.This axial compres sion downstream of the crimping chamber facilitatesthe overall yarn texturizing process.

This advantageous axial compression of the texturized yarn within theoutlet tube may be enhanced yet further by the provision of backpressure apparatus 116 positioned adjacent the outlet end of the tube104. More particularly, the tube 104 may be fashioned with an oblongopening or slot 118 in the surface thereof for permitting the entranceof a leaf spring 120. The spring 120 is mounted upon the tube 104 by amounting collar 122 and set screw 124.

The leaf spring 120 extends within the tube 104 substantially across theaxial passageway thereof and facilitates the back pressure maintainingcharacter of the outlet tube as initially provided by the arcuateconfiguration thereof. The back pressure provided by leaf spring 120further adds axial compaction to the yarn as it progresses in a loosemass through the outlet tube 104 and falls into the heat treatingchamber 24.

The presence of the spring 120 is particularly advantageous from thestandpoint of enhancing the versatility of the apparatus. Wheredifferent sizes of yarns are to be processed. the resistance to movementoffered by the bent tube alone may vary significantly in dependence uponthe size of the yarn, but the spring 120 tends to make reasonablyuniform the overall resistance to passage of the yarns. The spring isvery light in weight, so that its inertia characteristics do notcontribute significantly toward the production of nonuniformities in theyarn being processed.

The spring force exerted by the spring 120 preferably is small. itsprimary function is to assure the presence of sufficient resistance toprevent unimpeded flow of yarn out of the tube, and this can beaccomplished with a light force. it is in fact undesirable to imposelarge back pressures on the yarn outlet. When the back pressure becomesunduly large, the free exit of the filaments from the crimping zone isimpeded and there is a tendency for some of them to stay in contact withthe hot steam stream long enough to fuse slightly and adhere to oneanother. The development of such an undesirable situation is readilydetectable through examination of the yarn issuing from the outlet tube,and when such a situation does develop, it can be corrected easily bybending the spring a little to reduce its impeding force on the yarn.

In addition to the already noted advantages associated with the gradualincrease in axial compaction of the yarn within the outlet tube, theloose mass of yarn filaments compressed within the outlet tube serve asa muffler or noise barrier, and hissing or whistling noises generated bythe steam jet are attenuated. In this connection, in prior bouncecrimping devices, noise from the steam jet could readily exit throughthe yarn outlet passage and presented a highly undesirable noisepollution at the crimping apparatus which made working conditions aroundthe apparatus irritating and objectionable.

A further synergistic function of the outlet tube 104 is achieved by itscapacity to free yarn filaments which become lodged within theforaminous screen 62. More particularly, in some instances, individualyarn filaments tend to stick or become lodged in the openings within theforaminous member 62 and thus not rebound into the outlet tube asdesired. As noted in the background of the invention, nip rollers havebeen previously provided to correct such errant operation. With theprovision of the subject improved outlet tubular member, however, notonly is texturizing facilitated by axially compacting the yarn as theyarn passes from the texturizing chamber to a heat treating chamber, butthe plug of advancing texturized yarn formed within the outlet tube 104serves as a mass to pull upon and thus free individual yarn filamentswhich occasionally become embedded within the foraminous surface 62.

SUMMARY OF MAJOR ADVANTAGES In describing a preferred embodiment of animproved outlet tube structure in combination with a bounce crimpingapparatus, several highly advantageous aspects of the invention havebeen delineated.

in brief summary, the curved outlet tube 104 provides an increasingaxial compaction upon the yarn within the tube without reversely bendingthe yarn and thus facilitates the overall texturizing process. Further,the transition of a loose axially compressed plug of crimped filamentsconforming to the shape of the outlet 108 within the adapter 56 into acircular bundle in the outlet tube without permitting axial yarnbuckling minimizes the formation of irregularities during thetexturizing process.

Progressive axial compaction of the yarn through the outlet tube isfacilitated by a leaf spring positioned adjacent the outlet end of thetube 104.

Synergistically with the foregoing noted improvements in the texturizingprocess, noise pollution from process steam is substantially reduced bythe loose plug of axially compressed yam filaments within the outlettube. In a similar vein, the moving plug of yarn filaments serves as ameans for removing individual filaments which may occasionally becomeembedded within the foraminous crimping screen 62.

While the invention has been described with reference to preferredembodiments, it will be appreciated by those skilled in the art thatadditions, deletions. modifications and substitutions or other changesnot specifically described may be made which will fall within thepurview of the appended claims.

What is claimed is:

I. In bounce crimping apparatus for cxturizing multi-filamentthermoplastic yarn including:

a yarn texturizing chamber having an inlet, a fluid outlet alignedlongitudinally with said inlet, and a lateral yarn outlet,

means for introducing a heated fluid into said yarn texturizing chamberfor drawing yarn into said chamber,

a foraminous surface positioned across said fluid outlet of saidchamber, said heated fluid introduced into said chamber for drawing yarninto said chamber further serving to hurl the yarn against saidforaminous surface to axially compress and crimp the yarn filaments andrebound the yarn through said lateral outlet, and

means for collecting the crimped yarn while main taining the yarnsubstantially free from longitudinal tension.

the improvement comprising:

a tubular member connected to said lateral outlet in said chamber forconveying the crimped yarn from said chamber to said means forcollecting the crimped yarn and for continuously axially compacting theyarn as the yarn is conveyed to said means for collection,

said tubular member having,

a first end connected to said lateral outlet of said chamber forreceiving yarn rebounded from said foraminous surface, wherein a centrallongitudinal axis of said tubular member at said first end extends atright angles with respect to and intersects a central longitudinal axisof said chamber,

and a second end for directing the yarn from the tubular member intosaid means for collecting the crimped yarn, said tubular member beingcurved such that said curve provides resistance to the passage of yarntherethrough for axially compacting the yarn within the tubular member,and said tubular member being circular in cross section and having aninside diameter slightly greater than the largest dimension of saidlateral outlet of said yarn texturizing chamber whereby yarn hurledagainst said foraminous surface to be axially com pressed and crimpedand rebound through said lateral outlet may readily enter said tubularmember and conform to the shape thereof without substantial buckling ofthe yarn upon itself as said yarn exits said lateral outlet. 2. A bouncecrimping apparatus for texturizing multifilament thermoplastic yarn asdefined in claim 1,

wherein said means for conveying and axially compacting comprises:

a tubular member having an internal cross sectional area in the range offrom about one and one-half to about two times the area of said lateraloutlet.

3. A bounce crimping apparatus for texturizing multifilamentthermoplastic yarn as defined in claim 1 wherein the improvement furthercomprises:

member.

1. In bounce crimping apparatus for texturizing multi-filament thermoplastic yarn including: a yarn texturizing chamber having an inlet, a fluid outlet aligned longitudinally with said inlet, and a lateral yarn outlet, means for introducing a heated fluid into said yarn texturizing chamber for drawing yarn into said chamber, a foraminous surface positioned across said fluid outlet of said chamber, said heated fluid introduced into said chamber for drawing yarn into said chamber further serving to hurl the yarn against said foraminous surface to axially compress and crimp the yarn filaments and rebound the yarn through said lateral outlet, and means for collecting the crimped yarn while maintaining the yarn substantially free from longitudinal tension, the improvement comprising: a tubular member connected to said lateral outlet in said chamber for conveying the crimped yarn from said chamber to said means for collecting the crimped yarn and for continuously axially compacting the yarn as the yarn is conveyed to said means for collection, said tubular member having, a first end connected to said lateral outlet of said chamber for receiving yarn rebounded from said foraminous surface, wherein a central longitudinal axis of said tubular member at said first end extends at right angles with respect to and intersects a central longitudinal axis of said chamber, and a second end for directing the yarn from the tubular member into said means for collecting the crimped yarn, said tubular member being curved such that said curve provides resistance to the passage of yarn therethrough for axially compacting the yarn within the tubular member, and said tubular member being circular in cross section and having an inside diameter slightly greater than the largest dimension of said lateral outlet of said yarn texturizing chamber whereby yarn hurled against said foraminous surface to be axially compressed and crimped and rebound through said lateral outlet may readily enter said tubular member and conform to the shape thereof without substantial buckling of the yarn upon itself as said yarn exits said lateral outlet.
 2. A bounce crimping apparatus for texturizing multi-filament thermoplastic yarn as defined in claim 1, wherein said means for conveying and axially compacting comprises: a tubular member having an internal cross sectional area in the range of from about one and one-half to about two times the area of said lateral outlet.
 3. A bounce crimping apparatus for texturizing multi-filament thermoplastic yarn as defined in claim 1 wherein the improvement further comprises: said tubular member being operatively curved downwardly and having an opening formed in the surface adjacent the second end thereof; and leaf spring means connected to said tubular member adjacent said opening and extending through said opening into said tubular member for partially blocking the passage of crimped yarn through said tubular member to facilitate axial compaction of the yarn during its passage through said tubular member. 